WO1998055295A1

WO1998055295A1 - High strength baby wipe composite

Info

Publication number: WO1998055295A1
Application number: PCT/US1998/011726
Authority: WO
Inventors: Ramesh Srinivasan; Angelo Colace
Original assignee: Bba Nonwovens Simpsonville, Inc.
Priority date: 1997-06-05
Filing date: 1998-06-05
Publication date: 1998-12-10

Abstract

A composite nonwoven fabric suitable for use as a baby wipe comprises a layer of carded nonwoven fibers thermally bonded to a prebonded spunbonded-meltblown-spunbonded (SMS) or to a prebonded spunbonded-spunbonded (SS) fabric laminate (12). The layer of carded nonwoven fibers comprises polypropylene, polyester, rayon or cotton fibers, or a mixture thereof. A preferred embodiment comprises two outer carded layers (10a and 10b). The SMS or SS fabric laminates are made from polypropylene or polyethylene resins. The layers are thermally bonded at a plurality of discrete bonding points by passing the layers through engraved calender rolls (20a, 20b).

Description

HIGH STRENGTH BABY WIPE COMPOSITE

Field of the Invention

The invention relates generally to nonwoven web laminates and, more particularly, to composite nonwoven fabrics suitable for use as a baby wipe and formed by a thermal bonding process .

Background of the Invention

Nonwoven web laminates have application in a variety of disposable products, including wipes, garments, medical drapes and absorbent articles such as diapers, sanitary napkins and adult incontinence products, etc. It is desirable in these applications to combine the properties of a soft outer fabric for contact with the skin of a user with a durable and strong fabric having fluid absorption capacity.

One class of such nonwoven web laminates is commonly referred to as spunbonded-meItblown-spunbonded (SMS) laminates. These SMS laminates generally consist of nonwoven outer layers of spunbonded polyolefins and an interior layer of meltblown polyolefins. Laminates consisting of only nonwoven layers of spunbonded polyolefins without the interior meltblown layer also have application in disposable products, and are commonly referred to as spunbonded-spunbonded (SS) laminates. As used herein, the term "nonwoven web" refers to a web that has a structure of individual fibers or filaments which are interlaid, but not in an identifiable repeating pattern.

As used herein, the term "spunbonded fibers" refers to fibers which are formed by extruding molten thermoplastic material as filaments from a plurality of fine, usually circular capillaries of a spinnerette . Cooling air is fed to a quenching chamber wherein the filaments are cooled. The cooling air is then sucked through a nozzle, which accelerates the flow of air. The friction between the flowing air and the filaments creates a force which draws the filaments, i.e., attenuates the filaments to a smaller diameter. The drawn filaments are then passed through a diffusor and deposited on a conveyor belt to form a nonwoven web. A conventional spinbonding technique is disclosed in U.S. Patent No. 4,340,563 to Appel, which is incorporated herein by reference.

As used herein, the term "meltblown fibers" refers to fibers which are formed by extruding molten thermoplastic material as threads or filaments through a plurality of fine, usually circular capillaries of a die. A high- velocity, usually heated gas (e.g., air) stream attenuates the filaments of molten thermoplastic material to reduce their diameter. Thereafter, the meltblown fibers are carried by the high-velocity heated gas stream and are deposited on a collecting surface to form a web of randomly dispersed meltblown fibers. A conventional meltblowing technique is disclosed in U.S. Patent No. 4,707,398 to Boggs, which is incorporated herein by reference. Meltblown fibers differ from spunbonded fibers in that the extruded polymer strands are broken up and dispersed into individual fibers by the forced gas stream before being deposited on the collecting surface. In addition, the meltblown fibers are substantially cooled by the air so that they do not significantly bond together. Bonding of the web to retain integrity and strength occurs as a separate downstream operation.

In accordance with prior practice in the manufacture of baby wipes, a layer or layers of nonwoven webs are formed and saturated with lotion or other cleaning solution. Baby wipes are then packaged in containers which maintain moisture and allow for easy dispensing, such as a "pop-up" containers which dispense one wipe at a time when pulled through an opening in the container. Therefore, baby wipes must exhibit a certain strength to prevent tearing while maintaining softness and sufficient absorbency.

Two distinct types of baby wipes have been developed which cater, respectively, to the high and low end market segments. Low end baby wipes typically comprise air-laid nonwoven webs, for example, of pulp or paper. Air-laid webs comprise fibers which are distributed by air currents to give a random orientation within the web and a fabric with isotropic properties, but lacking in strength. High end baby wipes typically comprise spunlaced nonwoven webs. Spunlaced fabrics are produced by an expensive process which entangles fibers in a repeating pattern to form a strong fabric free of binders using high pressure water jets. Conventional high end baby wipes comprise polyester, polypropylene, rayon or blends thereof.

It is therefore a principal object of the invention to produce a baby wipe product that will offer significant cost advantage while delivering equal or better functional performance as conventional high end spunlaced baby wipes.

Summary of the Invention

The present invention is a nonwoven fabric laminate for use as a baby wipe product which is cost effective and has improved strength, durability and softness. More particularly, the baby wipe of the present invention is manufactured using a thermal bonding process by combining a layer of SS or SMS fabric with at least one fiber layer of absorbent, resilient and binder fibers. One fiber layer may be combined with an SS or SMS fabric to form a bi-laminate product, or two outer fiber layers may be combined with an intermediate SS or SMS fabric to form a tri-laminate product .

In a preferred embodiment, each fiber layer or layers preferably comprises a carded nonwoven web of fibers including thermoplastic fibers (e.g., polypropylene, polyethylene, polyester, or blends thereof) or non- thermoplastic fibers (e.g., rayon or cotton), or blends thereof. The SS or SMS fabric layer preferably comprises polypropylene or polyethylene.

The composite nonwoven fabric structure of the invention provides strength, absorbency, softness and improved cleaning ability at a reduced cost as compared to spunlaced wipes known in the art. The fabric's strength comes from the SS or SMS fabric layer which is composed of fine fibers and the improvement in absorbency and softness is primarily due to the addition of a carded fiber layer. The composite of the present invention is also lightweight, and has a textured surface which enhances cleaning ability. In accordance with the preferred method of manufacture, a layer of SS or SMS fabric is introduced between two layers of a blend of carded fibers and thermally bonded between heated calender rolls having a pressure from about 100 to 1200 pounds per linear inch (pli) , preferably 250-800 pli, and a temperature from about 250°F to 600°F, preferably 300- 400°F. Other objects, features and advantages of the present invention are described in detail below in conjunction with the drawings, as follows:

Brief Description of the Drawings

FIGS. 1A, IB and 1C illustrate the thermal bonding technique in accordance with the invention for the general example of a tri-laminate baby wipe product.

FIG. 2 is a schematic diagram showing a process line for the manufacture of a thermally bonded baby wipe composite in accordance with a preferred embodiment of the invention.

FIG. 3A is a schematic diagram showing a sectional view of a portion of a bond roll used for thermal bonding in accordance with one preferred embodiment of the invention.

FIG. 3B is a schematic diagram showing the arrangement of circular bond dots in a hexagonal pattern on the outer circumferential surface of the bond roll of FIG. 3A. FIG. 4 is a schematic diagram showing the construction of a conventional spunbonded-meltblown-spunbonded (SMS) fiber laminate.

FIG. 5 is a schematic diagram showing the essential components of a system for continuously producing an SS or SMS fiber laminate for use in making a high strength composite baby wipe material in accordance with a preferred embodiment of the invention.

Detailed Description of the Preferred Embodiments

In the present invention, a one-step bonding process is used for manuf cturing a nonwoven product using thermal bonding (heated calender) technology. The nonwoven product is produced by combining one or two nonwoven layer (s) of fibers with a prebonded nonwoven web laminate layer of SS or SMS fabric. When the SS or SMS fabric is sandwiched between two nonwoven fiber layers, a soft product having the same feel on both sides is made, referred to herein as a "tri- laminate" product. A "bi-laminate" product having different feel on each side may be made by bonding one nonwoven fiber layer to a prebonded SS or SMS fabric layer. An example of the general process for forming a nonwoven baby wipe product in accordance with the invention is illustrated in FIGS. 1A-1C. One or two outer nonwoven layers 10a, 10b and a prebonded SS or SMS fabric layer 12 are fed in superposed relation through the nip of a pair of heated calender rolls 20a, 20b. The calender rolls have a plurality of calendering points or lands 22a, 22b which come together to apply heat and pressure to the superposed layers fed in between. As shown in FIG. lb, application of suitable heat and pressure causes the fibers of the webs 10a, 10b to bond together and to bond to the SS or SMS fabric layer 12. As shown in FIG. lc, the heated calendering points 22a, 22b serve simultaneously to bond the layers together and to define indentations 30 in the outer surface 32 of nonwoven layers 10a, 10b. The result is that the layered structure is thermally point bonded with a textured surface . In FIG. 2, a process line is shown schematically for the manufacture of a nonwoven baby wipe as a continuous roll product. The thermoplastic or non-thermoplastic fibers are carded at card stations #1 and #2 and fed on card conveyors 14a, 14b, respectively, for the webs 10a, 10b of fibers. The prebonded SS or SMS fabric 12 is unwound from an unwind stand 16 and fed in superposed relation between the two carded webs on the card conveyors 14a, 14b, and the prebonded composite of SMS or SS fabric sandwiched between two carded webs is fed by conveyor 17 to hot calender rolls 20a, 20b to be thermally bonded and textured. Although FIG. 2 shows dual engraved calender rolls 20a, 20b, it is within the scope of this invention to form the baby wipe using a single engraved calender roll on the top 20a or on the bottom 20b. On entering the heated calender rolls, the thermoplastic fibers in the carded layer (s) 10a, 10b are bonded together and to the prebonded SS or SMS fabric layer 12 at the raised lands 22a, 22b to form a textured surface pattern. On exiting the calender rolls, the bonded and textured nonwoven fabric is wound up on a roll .

In accordance with a preferred method of manufacture, the temperature of the calender rolls may be in the range of 250-600°F, preferably 300-400°F. The pressure between the top and bottom rolls may be in the range of 100-1200 pounds per linear inch (pli), preferably about 250-800 pli. The line speed may be in the range of 50-600 feet per minute

(fpm) . Samples were produced at a line speed of 100-200 fpm. The bond pattern on either or both of the calender rolls can have any one of a number of different geometries including, but not limited to, Novonette #1, Novonette #2 and a repeating 7 -dot pattern. The total bonding area can be varied in the range of 5-36%. In accordance with a preferred embodiment, the engraving pattern on the surface of one of the calender rolls (either top or bottom) has a repeating 7-dot pattern wherein each repeating unit of the bond pattern comprises circular bond spots arranged with their centers at the vertices of a regular hexagon. The other calender roll is smooth. The geometry of the lands of the engraved roll is shown in FIG. 3A. As seen in FIG. 3B, each repeating unit of the bonding pattern is arranged in a hexagonal fashion. The hexagonal unit is repeated at a distance of 0.261 inch in the machine direction and a distance of 0.463 inch in the cross direction. Each hexagonal unit consists of a circular bond spot of 0.48-inch diameter at the center surrounded by an outer array of six circular spots of the same diameter at the vertices of a hexagon. The center-to-center distance of the outer array of circular spots is 0.949 inch. The outer circular spots are also radially spaced at a distance of 0.094 inch from the central circular spot. The aforementioned 7 -point dot bond pattern has a total of 115 bond spots per square inch, resulting in a total bond area of 19.1%.

In accordance with a second preferred embodiment of the invention, calender rolls engraved with a helical pattern of lands and grooves are used to thermally bond the layered structure to a bond area of about 25% (referred to herein as the "Novonette #2 pattern") . "Novonette #1" calender patterns produce fabrics having a bond area of about 27%. The lands may be generally defined as a spaced set of parallel ellipsoids extending equidistant from the axis of the rolls and in a plane which is inclined relative to the roll axes. The overall character of the bond area and fiber-displacement pattern will comprise three components: a highly compacted area where a land has traversed a land; more lightly compressed areas where a land on one roll has traversed a groove on the other roll; and a substantially unaffected are where a groove on one roll has traversed a groove on the other roll. The degree to which these areas are permanently impressed onto composite fabric material processed between such rolls will depend on the thickness of the composite fabric material, its nature and the pressures and temperatures used in processing. Novonette calendering rolls are disclosed in U.S. Patent No. 3,507,943 to Such et al . , which is incorporated herein by reference.

The fibers of the carded nonwoven layer (s) are preferably made of absorbent, resilient and binder fibers including thermoplastic fibers, for example, polypropylene, polyester, polyethylene, or blends thereof. Cellulosic fibers (e.g., rayon or cotton) may also be blended with the thermoplastic fibers. Carded nonwoven layers in accordance with this invention have a basis weight in the range of 5-60 grams, preferably 30-45 grams, and a thickness of 10-50 mils measured using a Thwing-Albert caliper at 0.26 psi . A description of several preferred fibers and their properties are shown in Table 1.

Manufactured by Wellman, Charlotte, North Carolina Manufactured by Hercules, Oxford, Georgia Manufactured by CourLaulds, LeMoyne, Alabama

Preferred prebonded SS or SMS fabric layers are commercially available from Veratec, Inc., Walpole, Massachusetts under the tradenames Veraspun™ and Everspun™, respectively. Both of these fabrics comprise polypropylene fibers. However, other thermoplastic fibers, for example, polyethylene, may be used to form the SS or SMS layer. It has been found that a polyethylene SS layer provides an improved textured effect, which is believed to enhance cleaning ability. SS or SMS fabric layers m accordance with this invention have a basis weight of 10-40 grams per square yard (gsy) and a thickness of 5-40 mils measured using a Thwing-Albert caliper at 0.26 psi . Preferred SS fabrics have a basis weight of 14-17.5 gsy and preferred SMS fabrics have a basis weight of 10-14 gsy.

FIG. 4 illustrates a typical SMS fabric layer 12 for use in the present invention comprising a meltblown fabric layer 4 of thermoplastic polymeric microfibers and two spunbonded fabric layers 6 and 8 each made of thermoplastic polymer filaments. The meltblown fabric layer 4 can be prepared by extruding a fiber- forming thermoplastic polymer resin in molten form through a plurality of fine, usually circular capillaries of a die. A high-velocity, usually heated gas (e.g., air) stream attenuates the filaments of molten thermoplastic material to reduce their diameter. Thereafter, the meltblown fibers are carried by the high- velocity heated gas stream and are deposited on a collecting surface to form a nonwoven web of randomly dispersed meltblown fibers. In accordance with a preferred embodiment, the thermoplastic polymeric microfibers of meltblown fabric layer 4 are polypropylene. Polymers other than polypropylene, such as nylon, polyethylene, polyester, and copolymers and blends thereof, may also be used.

Each of the spunbonded fabric layers 6 and 8 may be produced by continuously extruding a thermoplastic polymer through a plurality of fine, usually circular capillaries of a spinnerette. Cooling air is fed to a quenching chamber wherein the filaments are cooled. The cooling air is then sucked through a nozzle, which accelerates the flow of air. The friction between the flowing air and the filaments creates a force which draws the filaments, i.e., attenuates the filaments to a smaller diameter. The filaments are drawn to achieve molecular orientation and tenacity. The continuous filaments are then deposited in a substantially random manner to form a web of substantially continuous and randomly arranged, molecularly oriented filaments. Spunbonded fabric layers 6 and 8 are prebonded and thus have structural integrity. The preferred thermoplastic polymer used to make spunbonded fabric layers 6 and 8 is polypropylene, although nylon, polyethylene, polyester, and copolymers and blends thereof may be used.

In accordance with the conventional structure of an SMS fabric as seen in FIG. 4, the meltblown fabric layer 4 is sandwiched between the spunbonded fabric layers 6 and 8. All three of these fabric layers are then continuously bonded together by the application of heat and pressure to form the SMS fabric laminate 12. FIG. 5 shows a production line 30 for producing a prebonded SMS fabric laminate 12 for use in the present invention. This production line can be operated at a speed of 375 m/min. The equipment of production line 30 consists of an endless foraminous forming belt 32 wrapped around rollers 34 and 36. The belt 32 is driven in the direction shown by the arrows. The production line 30 includes a forming machine which has three stations: spunbond station 36, meltblown station 38 and spunbond station 40. First, the spunbond station 36 lays down a web 8 of spunbonded fibers 37 onto the carrier belt 32. Then the meltblown station 38 lays down a web 4 of meltblown fibers 39 onto the spunbonded web 8. Lastly, the spunbond station 40 lays down a web 6 of spunbonded fibers 41 onto the meltblown web 4. Alternatively, each of the component fabric layers may be formed separately, rolled, and later converted to an SMS fabric laminate offline.

The spunbond stations 36 and 40 are conventional extruders with spinnerettes which form continuous filaments of a polymer and deposit those filaments onto the forming belt 32 in a random interlaced fashion. Each spunbond station may include one or more spinnerette heads depending on the speed of the process and the particular polymer being used. Forming spunbonded material is a conventional process well known in the art.

The meltblown station 38 consists of a die 42 which is used to form microfibers 39. As the thermoplastic polymer exits the die 42, the polymer threads are attenuated and spread by high-pressure fluid, usually air, to form microfi- bers 39. The microfibers 39 are randomly deposited on top of the spunbond layer 8 and form a meltblown layer 4. The construction and operation of the meltblown station 38 for forming microfibers 39 are well known in the art.

Out of the forming machine, the SMS fabric laminate web 12 (see FIG. 5) is then fed through bonding rolls 44 and 46. The surfaces of the bonding rolls 44 and 46 are provided with a pattern of raised lands which apply heat and pressure to thermally spot bond the three layers together. The bonding rolls are heated to a temperature which causes the meltblown polymer to soften. As the meltblown web 4 passes between the heated bonding rolls 44 and 46, the composite material is compressed and heated by the bonding rolls in accordance with the pattern on the rolls to create a pattern of discrete bonding areas. Such discrete area or spot bonding is well known in the art and can be carried out by means of heated rolls or by ultrasonic bonding. The bond pattern is selected to provide desired fabric strength characteristics. The pattern bonding area is not limited in accordance with the present invention.

In accordance with a second preferred embodiment of the invention, a spunbonded fabric laminate (SS) is formed by operating only spunbond stations 36 and 40, i.e., meltblown station 38 is turned off. In this case, the bonding rolls 44 and 46 must be heated to a temperature which causes the spunbonded polymer to soften. The precursor SMS (or SS) fabric laminate exiting the bonding station is inherently hydrophobic . During trial runs, samples of baby wipes were manufactured in accordance with the above-parameters on both a commercial line and a pilot line similar to the line shown in FIG. 2, and subjected to various tests, including absorbency, sinktime, tensile strength, elongation, and fuzz production. The following examples illustrate the material composition ranges and properties of several preferred embodiments of the invention. All wet properties were tested using a proprietary baby lotion and a conventional baby lotion obtained by squeezing it out of commercially available baby wipes.

Example 1 :

The first group of baby wipes manufactured and tested comprise a 17.5 grams per square yard (gsy) hydrophilic polyproplene SS middle layer (Veratec Veraspun™) sandwiched between top and bottom carded fiber layers comprising the same blend of fibers and thermally bonded by calender rolls having the 7 -point bond pattern. Each carded web of the first sample (No. L4 1007.1) has a fiber composition of 50% 2.0 dpf x 38 mm polypropylene staple fibers (Herculon^® T117) and 50% 1.5 dpf x 40 mm rayon fibers (Courtaulds 18453). The carded webs of the second sample (No. L4 1007.4) have a fiber composition of 50% 2.6 dpf x 38 mm polypropylene staple fibers (Herculon^® Till) and 50% 2.0 dpf x 40 mm rayon fibers (Courtaulds 14561). The third sample (L4 1007.5) comprises carded webs having a fiber composition of 25% 2.6 dpf x 38 mm polypropylene (Herculon^® Till) , 25% 1.5 dpf x 38 mm polyester (Fortrel^® Type 472), and 50% 2.0 dpf x 40 mm rayon fibers (Courtaulds 14561) . Properties of these three samples are shown in Table 2.

TABLE 2

PROPERTIES SAMPLE NO

L4 1007 1 L4 1007 4 L4 1007 5

Total Weight (gsy) 53 40 52 10 60 30 Caliper (mils) 25 80 24 00 28 70 Absorbency (gm/gm) 11 53 10 74 11 64 Sinktime (sees) 3 40 2 70 2 53

Dry Strip Properties MD tensile (gm/in) 2 ,572 00 3,596 00 3,031 00 MD elongation (%) 20 30 44 10 31 30

CD tensile (gm/in) 772 30 3,596 00 3,031 00 CD elongation (%) 41 70 63 20 57 90

Wet Strip Properties MD tensile (gm/m) 3 ,229 00 3,672 00 3,551 00 MD elongation (%) 22 20 39 50 34 20

CD tensile (gm/m) 848 50 1,322 00 825 20 CD elongation (%) 42 60 52 10 56 60

Fuzz (dry sample) (mgs) 27 10 14 90

As can be seen in Table 2, replacing the high tenacity, low elongation T117 hydrophilic polypropylene fibers in sample L4 1007.1 with low tenacity, high elongation Till hydrophilic fibers m sample L4 1007.4 resulted in a 40% increase in strength in the machine direction, and 81% increase in strength in the cross direction, and a 45% reduction in fuzz generation. Sample L4 1007.5 was found to possess a softer hand which can be attributed to the introduction of polyester fibers into the outer carded fiber blends. All three samples exhibited good absorbency. Sink times do not play a significant roll in the performance of these nonwoven composite fabrics because they are sold as pre-moistened baby wipes.

Example 2 :

The second group of samples comprise a middle layer of polypropylene SMS fabric (Everspun™, manufactured by Veratec, Inc., alpole, Massachusetts) and outer carded layers each having a different matrix of fibers. The top layer comprises 100% polypropylene (PP) and the bottom layer comprises a blend of polypropylene, polyester (PET) and rayon fibers. The fiber composition of each layer in these samples is shown in Table 3 and the properties of the samples are shown in Table 4.

TABLE 3

MATERIAL SAMPLE NO. COMPOSITION L4 1010.2 L4 1010.6 L4 1019.2

Calender Pattern 7-Point 7 - Pomt Novonette #2 Top Layer 100% PP 100% PP 100% PP

Herculon^® T117 Herculon^® T117 Herculon^® T116

Middle Layer 13 gsy PP SMS 13 gsy PP SMS 10 gsy PP SMS

Everspun™ Everspun™ Everspun™ Hydrophobic Hydrophobic Hydrophilic Bottom Layer 28% PP 33% PP 33% PP

Herculon^® T117 Herculon^® T117 Herculon^® T117 36% PET 33% PET 33% PET

Fortrel^® Type 472 Hoechst-Celanese Fortrel^® Type 472 Type 224¹ 6.0 dpf x 38 mm

36% Rayon 33% Rayon 33% Rayon

Courtaulds Courtaulds Courtaulds

14561 20762 18453

Manufactured by Hoechst-Celanese Corporation, Charlotte, North Carolina

TABLE 4

PROPERTIES SAMPLE NO.

L4 1010.2 L4 1010.6 L4 1019.2

Total Weight (gsy) 51.70 53.10 47.60 Caliper (mils) 24.80 27.40 25.30 Absorbency (gm/gm) 10.85 11.14 12.58 Sinktime (sees) 4.61 7.96 3.54 Dry Strip Properties : MD tensile (gm/m) 2 ,912.00 3,350.00 1, 132.00 MD elongation (%) 22.10 24.30 19.20

CD tensile (gm/m) 657.00 662.70 218.70 CD elongation (%) 36.50 53.30 54.50 Wet Strip Properties: MD tensile (gm/m) 3 , 204.00 3,427.00 1,173.00 MD elongation (%) 22.70 24.50 21.60

CD tensile (gm/m) 622.50 752.00 243.50 CD elongation (%) 37.20 44.70 54.10 Fuzz (dry sample) (mgs) 28.30 24.60 4.50

Sample No. L4 1019.2 exhibited a significant reduction in fuzz generation, about 80-85% less than in Sample Nos. L4 1010.2 and L4 1010.6, and about 70% less than Sample No. L4 1007.4 in example 1. This improvement can be attributed to the increased bond area (25%) provided by the Novonette #2 calender pattern. The 13 gsy Everspun™ middle layer used in Sample Nos. L4 1010.2 and L4 1010.6 resulted in improved tensile strengths comparable to those obtained in the fabrics of example 1 which comprise 17.5 gsy Veraspun™ .

Example 3 :

The following composite baby wipe fabrics were made using partially-bonded polyethylene SS fabrics in the middle layer and fiber layers on both sides comprising the same fiber or fiber blend. The polyethylene (PEN) spunbonded fabrics were manufactured on a pilot line, unlike the previously mentioned Veraspun™ SS and Everspun™ SMS fabrics which were manufactured on a commercial line. These samples had a deep embossed look, which enhance texture and aesthetics of the wipe. It is also believed that these samples will have increased cleaning ability resulting from the deeper embossments and polyethylene spunbonded layer. The fiber composition and properties of these samples are shown in Tables 5 and 6, respectively.

TABLE 5

MATERIAL SAMPLE NO. COMPOSITION TL10200.2 TL10200.3 TL10200.4

Calender Pattern Novonette #1 Novonette #1 Novonette #1 Top and 100% Rayon 100% Rayon 50% PP

Bottom Layers Courtaulds 18453 Courtaulds 18453 Herculon^® T101

50% Cotton

Middle Layer 30 gsy PEN SS 20 gsy PEN SS 20 gsy PEN SS

Hydrophobic Hydrophobic Hydrophobic

TABLE 6

PROPERTIES SAMPI _E NO

TL10200 2 TL10200 3 TL10200 4

Total Weight (gsy) 71 20 64 40 60 90 Cal per (mils) 25 00 22 30 23 50 Absorbency (gm/gm) 8 41 8 99 n/a

Dry Strip Properties MD tensile (gra/in) 2, 193 00 1, 787 00 3,490 00 MD elongation (%) 20 20 16 60 11 90

CD tensile (gm/in) 663 00 485 70 575 30 CD elongation (%) 54 90 43 40 46 90

Wet Strip Properties MD tensile (gm/m) 1, 711 00 1,521 00 2,902 00 MD elongation (%) 38 38 35 60 15 00

CD tensile (gm/in) 605 10 415 80 513 10 CD elongation (%) 78 60 67 20 58 90

From the samples tested m these examples, the following observations were made. All of the sample materials had a substantially lower material and fabrication cost than conventional spunlaced nonwovens used for baby wipes, while delivering comparable functional performance to commercially available high-end baby wipes. The samples further exhibited a unique texture and appearance in the wet condition (i.e., in the presence of baby lotion) which gives the baby wipes of this invention a superior aesthetic look to conventional baby wipes. Further advantages of the baby wipes of this invention are apparent when compared to samples of commercially available baby wipes, as shown in Table 7. Commercially available samples A - E are the less expensive air-laid nonwoven baby wipes. Samples F - G are the more expensive spunlaced nonwoven baby wipes. TABLE: 7

PROPERTIES A B C D E F G

Weiq t gsy 54 60 45 40 52 00 67 30 52 60 60 90 56 80 gsm 65 30 54 30 62 20 80 50 62 90 72 80 67 90

Caliper mils 26ι 90 17 80 24 30 33 20 22 80 21 90 21 50 microns 683 30 452 10 617 20 843 30 579 10 556 30 546 10

Dry Strip Tensile MD (gm/m) 940 00 1,985 00 787 60 587 60 944 30 7,856 00 7, 231 00 MD (gm/cm) 370 10 781 50 310 10 231 30 371 80 3,092 90 2,,846 80 CD (gm/in) 365 10 463 20 675 80 310 20 538 40 2,407 00 3_;,230 00 CD (gm/cm) 143 70 182 40 266 10 122 10 212 00 947 60 1,,271 70 0 Dry Strip Elonqation MD (%) 5 90 11 30 13 30 16 10 11 90 23 90 25 00 CD (%) 13 80 31 70 20 50 30 10 19 40 105 50 75 60

Wet Strip Tensile MD (gm/m) 498 10 1,345 00 357 00 706 40 330 50 6,065 00 6. ,038 00 MD (gm/cm) 196 10 529 50 140 60 278 10 130 10 2,387 80 2 ,377 20 CD (gm/in) 197 60 295 90 302 50 302 70 300 30 2,310 00 2 ,799 00 CD (gm/cm) 77 80 116 50 119 10 119 20 118 20 909 40 1 ,102 00 0 Wet Strip Elonqation MD (%) 8 10 13 70 16 30 16 10 15 00 20 10 25 00 CD (%) 18 70 38 00 22 50 35 40 22 50 94 30 81 70

Fuzz (mg) 5 (dry sample) Fuzz s de only 5 10 1 50 0 20 4 60 0 20 3 10 0 70

Absorbency gm/gm 10 39 8 77 10 08 11 03 9 08 7 92 7 95

Sink Time (sees) 3 73 13 27 2 25 2 18 1 99 1 56 1 66 D

Several preferred embodiments of the invention have been disclosed for the purpose of illustration. Variations and modifications of the disclosed preferred embodiments which fall within the concept of this invention will be 5 readily apparent to persons skilled in the arts of thermal bonding and disposable hygienic nonwoven products, including variations in fibers, fiber blends and process conditions. All such variations and modifications are intended to be encompassed by the claims set forth hereinafter.

Claims

1. A composite nonwoven fabric comprising a prebonded spunbonded-meltblown- spunbonded fiber laminate thermally bonded to a nonwoven layer of absorbent, resilient and binder fibers at a plurality of discrete bonding points.

2. The composite nonwoven fabric of claim 1, wherein the nonwoven layer comprises a carded web of fibers.

3. The composite nonwoven fabric of claim 2, wherein the carded web comprises fibers selected from the group consisting of thermoplastic fibers, non-thermoplastic fibers, or a mixture thereof.

4. The composite nonwoven fabric of claim 2, wherein the carded web comprises fibers selected from the group consisting of polypropylene, polyester, polyethylene, rayon, cotton, or blends thereof.

5. The composite nonwoven fabric of claim 4, wherein the meltblown and spunbonded fibers in the fiber laminate are made of polypropylene.

6. The composite nonwoven fabric of claim 5, wherein the fabric comprises a top carded nonwoven layer, an intermediate spunbonded-meltblown-spunbonded fiber laminate and a bottom carded nonwoven layer.

7. The composite nonwoven fabric of claim 6, wherein the top carded nonwoven layer comprises polypropylene fibers and the bottom nonwoven layer comprises a blend of polypropylene, polyester and rayon fibers.

8. The composite nonwoven fabric of claim 5, wherein the spunbonded-meltblown- spunbonded fabric laminate has a weight of 10-14 gsy.

9. A composite nonwoven fabric comprising a prebonded spunbonded-spunbonded fiber laminate thermally bonded to a nonwoven layer of absorbent, resilient and binder fibers at a plurality of discrete bonding points.

10. The composite nonwoven fabric of claim 9, wherein the nonwoven layer comprises a carded web of fibers.

11. The composite nonwoven fabric of claim 10, wherein the carded web comprises fibers selected from the group consisting of thermoplastic fibers, non-thermoplastic fibers, or a mixture thereof.

12. The composite nonwoven fabric of claim 10, wherein the carded web comprises fibers selected from the group consisting of polypropylene, polyester, polyethylene, rayon, cotton, or blends thereof.

13. The composite nonwoven fabric of claim 12, wherein the spunbonded fibers in the fiber laminate are made of polypropylene .

14. The composite nonwoven fabric of claim 13, wherein the fabric comprises two outer carded nonwoven layers and an intermediate spunbonded-spunbonded fiber laminate sandwiched therebetween .

15. The composite nonwoven fabric of claim 14, wherein the outer carded nonwoven layers comprise a blend of polypropylene and rayon fibers.

16. The composite nonwoven fabric of claim 15, wherein the spunbonded-spunbonded fabric laminate has a weight of 14-17.5 gsy.

17. The composite nonwoven fabric of claim 12, wherein the spunbonded fibers in the fiber laminate are made of polyethylene .

18. The composite nonwoven fabric of claim 17, wherein the fabric comprises two outer carded nonwoven layers and an intermediate spunbonded-spunbonded fiber laminate sandwiched therebetween.

19. The composite nonwoven fabric of claim 18, wherein the spunbonded-spunbonded fabric laminate has a weight in the range of 14-17.5 gsy.

20. The composite nonwoven fabric of claim 19, wherein the outer carded nonwoven layers comprise rayon fibers.

21. The composite nonwoven fabric of claim 19, wherein the outer carded nonwoven layers comprise a blend of polypropylene and cotton fibers.

22. A method of manufacturing a composite nonwoven fabric, comprising thermally bonding a prebonded spunbonded- meltblown- spunbonded fiber laminate to a nonwoven layer of absorbent, resilient and binder fibers at a plurality of discrete bonding points.

23. The method as defined in claim 22, wherein the prebonded fiber laminate is thermally bonded to the nonwoven fiber layer by a pair of heated calender rolls, at least one of the rolls having an engraved surface.

24. The method as defined in claim 23, wherein the nonwoven fiber layer is a carded web of fibers selected from the group consisting of polypropylene, polyester, polyethylene, rayon, cotton, or blends thereof, and the meltblown and spunbonded fibers in the fiber laminate are made of polypropylene .

25. The method as defined in claim 24, wherein the calender rolls are heated to a temperature in the range of 300-400┬░F and apply pressure of about 250-800 pli.

26. The method as defined in claim 24, wherein the surface of the calender rolls is engraved with a 7 -point bond pattern.

27. The method as defined in claim 24, wherein the surface of the calender rolls is engraved with a Novonette bond pattern.

28. A method of manufacturing a composite nonwoven fabric, comprising the steps of: forming a nonwoven layer of fibers; placing the nonwoven layer in superposed relation to a prebonded spunbonded-spunbonded fabric laminate; conveying the nonwoven layer and the prebonded fabric laminate through a pair of heated calender rolls such that the nonwoven layer and fabric laminate are bonded together under the application of heat and pressure at a plurality of discrete bonding points.

29. The method as defined in claim 28, wherein the nonwoven fiber layer is a carded web of fibers selected from the group consisting of polypropylene, polyester, polyethylene, rayon, cotton, or blends thereof, and the spunbonded fibers in the fiber laminate are selected from the group consisting of polypropylene and polyethylene.

30. The method as defined in claim 29, wherein the calender rolls are heated to a temperature in the range of 300-400┬░F and apply pressure of about 250-800 pli.